This invention relates to optical fiber handling systems, and more particularly to optical fiber distribution frames having integral intelligent elements.
Many telecommunications applications utilize an optical fiber network of interconnected optical fiber cables to enable optical communications between network locations. Ordinarily, a unique fiber routing will be required to transmit light pulses between network locations. Over this unique route, light pulses may be propagated across several different fibers. At each transition from one fiber to another, individual fibers are connected, thereby enabling light pulses to be carried between a first fiber and a second fiber. In many cases, such as at a central office for the communications system, large numbers of fiber connections must be made and a fiber administration system is employed to manage the various connections.
In many fiber administration systems, as the optical fibers in a network enter the central office, they are directed into an optical fiber distribution frame (FDF) where the individual optical fibers are terminated in an organized manner. Such fiber administration systems are exemplified by the LGX(copyright) fiber administration system that is currently manufactured by Lucent Technologies of Murray Hill, N.J., the assignee herein.
The FDF accommodates the placement and management of optical jumpers for interconnecting or cross connecting optical transmission equipment and outside plant (OSP) fibers. The FDF typically includes an upright structural framework or support member, a space or bay within the support member to hold racks or shelves of terminal equipment, a pair of distribution rings adjacent each shelf to convey fibers vertically, and an upper and lower raceway, each having space to convey fibers horizontally to the terminal equipment. The upper raceway further includes an arcuate support member at each end for supporting the optical fibers and guiding them through a minimum radius in transition from vertical to horizontal. That minimum radius corresponds to the minimum bend radius for the fiber (a radius determined to avoid damage to, or light leakage from a fiber which can occur with a bend in the fiber exceeding that radius). A minimum bend radius of at least two inches is generally considered safe, and is typical.
Heretofore, FDF frames comprised passive optical jumpers with few if any electrical components. Recent practice has been to manage the OSP by including test modules containing active electrical components, or intelligent elements, within the FDF frame. Such test modules may include one or more optical switches, a remote test unit, a monitor, a writing shelf and keyboard, a test system control, a modem, and a printer. To support the intelligent elements within the FDF, it is now necessary to provide power, ground, and electrical communications.
The trend in recent years has been to pack ever increasing numbers of optical fibers into a FDF raceway. The resulting high fiber density has made it very difficult to locate test or support modules in the portion of the FDF occupied by the fiber distribution shelves because the cable density makes severely limits access to such modules. Moreover, open space for intelligent elements is highly limited.
Accordingly, there is a need to provide an optical fiber distribution frame having integral intelligent elements within the physical envelope of the FDF.
There is a further need to provide an optical fiber distribution frame of the type described and that includes space for the intelligent elements while maintaining accessibility for installing and removing optical fiber jumpers; and
There is a yet further need to provide an optical fiber distribution frame of the type described and that includes power, ground, and electrical communications for the intelligent elements.
In accordance with the present invention, there is provided a fiber distribution frame comprising an upright support member having opposite upper and lower ends, and opposite left and right sides. An upper raceway is located adjacent the upright support member upper end. The upper raceway has opposite left and right ends adjacent the upright support member left and right ends respectively. The upper raceway also has opposite left and right arcuate support members adjacent the upper raceway left and right ends respectively, for supporting and guiding optical fibers. The arcuate support members each have a predetermined radius. The upper raceway and the arcuate support members together define a first space that is adapted to receive at least one active electrical component.
In a further embodiment, a lower raceway is provided adjacent the upright support member lower end. The lower raceway has opposite left and right ends adjacent the upright support member left and right ends respectively. The lower raceway defines a second space that may also be adapted to receive at least one active electrical component.